Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/66—Polyesters containing oxygen in the form of ether groups
  • C08G63/668—Polyesters containing oxygen in the form of ether groups derived from polycarboxylic acids and polyhydroxy compounds
  • C08G63/672—Dicarboxylic acids and dihydroxy compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
  • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
  • C08G63/16—Dicarboxylic acids and dihydroxy compounds
  • C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
  • C08G63/181—Acids containing aromatic rings
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/06—Unsaturated polyesters

Definitions

• thermoplastic saturated polyester low profile additives for use with unsaturated polyesters and unsaturated monomers to make molded parts, especially vehicle parts.
• These low profile additives are made by reacting saturated diacids having a major portion of aromatic diacids with glycols, a portion of which are asymmetrical glycols.
• the aromatic diacid containing reactant is obtained by glycolysis of ground polyethylene terephthalate using an asymmetrical glycol forming a low molecular weight oligomeric glycol.
• thermosetting polyester resins for exterior auto and truck parts
• plastic materials such as fiberglass-reinforced thermosetting polyester resins for exterior auto and truck parts
• These cured resin materials have been successful because they are strong, heat resistant and enable molders to form one plastic part instead of several metal parts.
• thermosetting composites are difficult to mold without seriously compromising the surface cosmetics of the finished part.
• material suppliers and molders have worked to continuously improve the surface smoothness and dimensional stability of composite parts.
• thermoplastic polymer additives are used to improve surface quality of molded thermosetting plastic parts. These materials are called low profile additives because they decrease surface roughness and improve surface smoothness or "profile" by reducing the shrinkage of the thermosetting resin as a part is cured during molding. When significant cure shrinkage occurs, a cross section of the surface appears rough under high magnification showing large peaks and valleys. When cure shrinkage is reduced, the surface is smoother, and its cross section appears smoother, having lower peaks and shallower valleys. The objective of an effective low profile additive is to reduce the difference between the highest peaks and shallowest valleys to a minimum. Even the best low profile additives however, do not achieve a mirror-like surface.
• thermoplastic polymers used as low profile additives to control reaction shrinkage and improve the surface smoothness when curing unsaturated polyester resins and vinyl ester resins include polystyrene, polyesters, polymethyl methacrylate, polyvinyl acetate, polyurethanes, polyglycols, and their various copolymers.
• U.S. Pat. No. 3,959;209 Koppers lists polymeric thermoplastics which reduce the shrinkage of thermosetting resin formulations as they are cured and thus effectively produce articles having smooth, high quality cosmetic surfaces.
• Listed in U.S. Pat. No. 3,959,209 are homopolymers of ethylene, styrene, vinyl toluene, alkyl methacrylates, alkyl acrylates, various copolymers of vinyl chloride and vinyl acetate, styrene and acrylonitrile, methyl methacrylate and alkyl esters of acrylic acid, methyl methacrylate and styrene, methyl methacrylate, and acrylamide.
• thermoset molding compounds can sometimes improve other properties of thermoset molding compounds.
• U.S. Pat. No. 4,421,894 Olin describes a polyurethane oligomer modifier for incorporation into thermosetting polyester resin formulations which imparts improved impact properties to the often brittle thermoset resins in addition to reducing shrinkage during curing.
• U.S. Pat. No. 5, 116,917 Ashland Oil describes a saturated polyester low profile additive for vinyl ester resin systems made from dibasic acid and an ethylene oxide/propylene oxide polyether polyol having an ethylene oxide/propylene oxide molar ratio ranging from 0.1 to 0.9.
• polyester low profile additives are thermoplastic polyesters. This versatility is due to the wide variety of polyester copolymers that can easily be prepared, thus polyester low profile additives can be custom designed for a particular function in the unsaturated base resin of interest. Most polyester low profile additives are made from aliphatic dibasic acids or anhydrides such as glutaric, adipic, sebacic or azeleic, and glycols based on ethylene oxide or propylene oxide. These low profile additives are usually easy to prepare and formulate, have good compatibility in styrene and base resins, and show excellent shrinkage control which produces a high quality cosmetic surface.
• low profile additives are also prepared from aromatic dibasic acids or arthydrides such as phthalic, isophthalic and terephthalic, and glycols or lactones.
• aromatic dibasic acids or arthydrides such as phthalic, isophthalic and terephthalic, and glycols or lactones.
• Such polyesters are often more difficult to prepare, less soluble in styrene, less compatible in other polyesters, and typically show more cure shrinkage and reduced surface smoothness.
• they are usually tougher, with higher glass transition temperatures and melting points, and are more resistant to transesterification. This toughness yields increased mechanical properties for composite parts, especially at elevated temperatures.
• molding formulations are often premixed and stored prior to use, the possibility of transesterification between the low profile additive and base resin always exists.
• the low profile additives of this invention are prepared primarily from isophthalic and terephthalic acid and a variety of symmetrical and asymmetrical dihydric alcohols or glycols.
• Resistance to transesterification is primarily a function of the aromatic diacids content and is approximately proportional to the molar ratio of aromatic to aliphatic diacids. Resistance is best when there is a major portion of aromatic diacids.
• compatibility in styrene and unsaturated base resins and effectiveness at reducing cure shrinkage and improving surface smoothness is mainly a function of the variety and structure of glycols used and the number average molecular weight (Mn) of the polymer,
• glycols containing a substantial amount of asymmetrical materials such as propylene, dipropylene, polypropylene, and 2-methyl 1,3-propanediol show increased effectiveness when used to prepare low profile additives,
• the mechanical properties of the composite increase as the mechanical properties of the low profile additive increase.
• This invention is a resin composition useful for forming cured, molded articles such as automobile parts comprising a thermoset unsaturated polyester resin, one or more olefinically unsaturated monomers copolymerizable with said unsaturated polyester, and a saturated thermoplastic low profile additive which is compatible with the uncured resin molding formulation and becomes insoluble or incompatible during the curing reaction of the unsaturated polyester and monomer.
• the additive of this invention has a number average molecular weight (Mn) between 3,000 and 20,000. Such molecular weights may be reached by esterification or esterification followed by linking the polyesters through their terminal acid or hydroxyl end groups with multifunctional epoxides or isocyanates.
• thermoplastic low profile additive component of this invention is made by esterifying, or cooking, dicarboxylic acids or their anhydrides with glycol. Cooking may also be followed by linking the polyesters through their terminal hydroxyl or acid end groups with multifunctional isocyanates or epoxides to adjust the number average molecular weight. Such methods are well known by those skilled in the art of polyester technology.
• Typical reactants include diacids such as adipic acid, phthalic acid (anhydride), isophthalic acid and terephthalic acid, and glycols such as ethylene, diethylene, propylene, and dipropylene glycols, 2-methyl 1,3-propanediol, 1,4-butanediol and hexanediol.
• diacids such as adipic acid, phthalic acid (anhydride), isophthalic acid and terephthalic acid
• glycols such as ethylene, diethylene, propylene, and dipropylene glycols, 2-methyl 1,3-propanediol, 1,4-butanediol and hexanediol.
• Useful linking molecules include polyepoxides such as the glycidyl ethers of bisphenol A, phenol-formaldehyde novolaks, aliphatic fatty acids and esters, glycols and polyether glycols, polyamines and cyclohexenes which yield cycloaliphatic epoxides.
• Polyisocyanates such as toluene diisocyanate (TDI) and methylene di-para-phenylene isocyanate (MDI), are well known and useful.
• the preferred epoxy linking compound is the diglycidyl ether of bisphenol A[4, 4'-(1-methylethyiidene) bisphenol polymer with chloromethyl oxirane [CAS #25068-38-6].
• Polyester oligomers can easily be joined with polyepoxides by nucleophilic addition if they are terminated by a nucleophilic functional group, such an acid, or any group that could be reacted to yield an acid.
• the polyester can be cooked to yield hydroxyl terminal groups.
• Such an oligomer is easily linked using a multifunctional isocyanate such as TDI or MDI to form a polyurethane.
• the multifunctional epoxide or isocyanate linking moiety would usually be less than 15 weight percent of the final low profile additive product; preferably it would be less than 10 weight percent; and most preferably it would be less than 5 weight percent.
• the Mn of a polyester prepolymer suitable for this invention typically averages 1000 to 9000, and the Mn of the final low profile additive produced is 3,000 to 20,000, and preferably between 6000 and 16,000.
• the low profile additive of this invention is incorporated into thermosetting molding formulations to control shrinkage during cure.
• the thermosetting resins used may include conventional unsaturated polyesters, vinyl esters, and hybrid unsaturated polyesters which contain epoxy or urethane linkages.
• the low profile additive may be used in any effective proportion.
• the low profile additive is added in a proportion ranging from about 5 to about 30 parts by weight per 100 parts by weight of unsaturated polyester resin plus copolymerizable solvent.
• the additive comprises about 8 to about 20 parts by weight per 100 parts by weight of the polyester resin plus copolymerizable solvent.
• thermosetting unsaturated polyester resins are prepared by reacting dicarboxylic acids or their anhydrides with glycols, using methods and reactants well known in the polyester art.
• Typical reactants include diacids and anhydrides such as phthalic acid, phthalic anhydride, maleic acid, maleic anhydride, and glycols, such as ethylene glycol, diethylene glycol, propylene glycol, butanediol and hexanediol.
• the formed polyesters and the additives are diluted for use by dissolving them in reactive copolymerizable solvents.
• Such copolymerizable solvents include ethylenically unsaturated compounds such as styrene, vinyl toluene, methacrylic esters, acrylic esters, divinyl benzene, various multi-functional acrylates and methacrylates and diallyphthalate.
• the polymerization and curing of the additive containing polyester resin system is effected using well-known procedures, preferably in the presence of a polymerization catalyst. Curing temperature is dependent on the particular catalyst used. Commonly used catalysts are free radical generating catalysts such as peroxide or azo type compounds.
• Typical peroxy catalysts are organo peroxides and hydroperoxides such as benzoyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, lauryl peroxide, cyclohexanone peroxide, t-butyl perbenzoate, t-butyl hydroperoxide, t-butylbenzene hydroperoxide, cumene hydroperoxide, and t-butyl peroctoate.
• Typical azo compounds are azobisisobutyronitrile, 2-t-butylazo-2-cyano-4-methylpentane, and 4-5-butylazo-4-cyano-valeric acid.
• the preferred catalyst is t-butyl perbenzoate.
• the catalyst generally is used in an amount from about 0.1 to about 10 parts by weight per 100 parts by weight of thermoset resin, reactive solvent and low profile additive.
• composition of the present invention may also contain other standard ingredients, such as fillers (e.g., finely divided solids include CaCO 3 , clay, alumina, talc or glass microspheres) and reinforcement materials (e.g., chopped fiber glass, carbon fibers, asbestos fibers or boron nitride whiskers).
• Other ingredients may include internal mold release agents, such as calcium, zinc, magnesium, or sodium stearate.
• Pigments, dyes, stabilizers and viscosity modifiers e.g., Group II metal oxides and hydroxides, such as magnesium oxide
• Other low shrink or impact additives also may be included.
• a typical formulation generally contains reinforcement materials in an amount ranging from about 20 to about 300 parts by weight per 100 parts by weight of the polyester resin, copolymerizable solvent, plus low profile additive oligomer and from about 50 to about 1,000 parts by weight of fillers.
• this invention is a saturated polyester low profile additive made using a major portion of saturated aromatic diacid, a minor portion of saturated aliphatic diacid and a glycol mixture containing linear and asymmetrical glycols.
• the polyester may be further linked with epoxy or isocyanate compounds.
• this invention is a saturated polyester low profile additive made using an asymmetrical glycol and saturated aliphatic acid to glycolize and digest ground recycled polyethylene terephthalate polymer.
• This polyester can also be linked with multifunctional epoxy or isocyanate compounds.
• This second polyester contains about 50 percent recycle content.
• asymmetrical glycols are those as: ##STR1##
• the most preferred asymmetrical glycol is 2-methyl 1,3 Propanediol.
• the symmetrical glycols are those such as: ##STR2##
• this invention is a low profile additive having a major portion of an aromatic compound which is an oligomer obtained from ground recycled polyethylene terephthalate (PET).
• PET polyethylene terephthalate
• Recycle ground polyethylene terephthalate polymer is obtained from various sources in the form of film, bottles and chunks.
• One source is Resin Management, Tampa, Fla.
• the mixture was heated slowly to 225° C., removing H 2 O and held for 15 to 16 hours until the acid value was 26.8 and hydroxyl value was about 4.
• the temperature was reduced to 171 ° C. and about 130 grams EPON 828 epoxy resin (Shell Chemical Co.) and 2.8 grams tetrabutylphosphonium acetate (70% NV in methanol) [Johnson Matthey, Alfa Aesar, Ward Hill, MA 01835-0747; product code: 56179]were charged.
• the acid value was reduced to 10.0.
• About 2600 g of polymer product was cut to 50% nonvolatiles in styrene and inhibited with 200 ppm tert-butyl catechol.
• the mixture was heated slowly to 225° C., removing H 2 O and held for about 9 hours until the acid value was 39 and 1 g of Fascat 4100 catalyst (M&T Chemical, Rahway, N.J.) was added. At 15 hours and an acid value of about 31, 1 g of Fascat catalyst was again added. After no significant change in acid value in 3 hours, the hydroxyl value was checked and found to be about 2. The temperature was reduced and about 35 g of the glycol mixture in the initial charge was added. The acid value was reduced to 12.3 over the next 9 hours. About 2000 g of polymer product was cut to 50% nonvolatiles in styrene and inhibited with 200 ppm tertbutyl catechol. The number average molecular weight (Mn) of the polyester low profile additive, measured by end group analyses, was about 7400.
• Mn number average molecular weight
• a high recycle containing low profile additive was prepared from the glycolysis product of diethylene glycol (a symmetrical glycol) and polyethylene terephthalate (PET) and adipic acid as follows. PET and 900 g diethylene glycol (1/0.8 molar ratio) were heated and held at 220° C. for 4 hours.
• the glycolized PET and 424 g adipic acid were charged to a 2-liter resin kettle and heated slowly to about 226° C. as water was removed. An acid value of 21.2 and a hydroxyl value of about 13 was reached after 6 hours. About 19 g of adipic acid was added and an additional 6 hours reduced the acid value to 25.0 and the hydroxyl value to 3 to 4.
• the reactor was cooled to 185° C. and 57.9 g of Epon 828 epoxy resin and 0.98 g of tetrabutylphosphonium bromide catalyst were charged. The acid value was reduced to 7.8 in about an hour.
• the 1250 g of polymer was cut to 50% nonvolatiles with styrene inhibited with 200 ppm of t-butyl catechol.
• a high recycle containing low profile additive was prepared from the glycolysis product of 2-methyl 1,3-propanediol and polyethylene terephthalate (PET) and adipic acid as follows:
• the PET and glycol were charged to a 4-liter resin kettle, heated and held between 220° C. and 222° C. for about 4 hours.
• the product was a soft well digested paste when cold.
• the adipic acid and Antifoam A were charged, and the temperature were raised to 225° C. as water was removed.
• the reactor was cooled to 180° C.
• 133 g Epon 828 epoxy resin and 2.04 g of tetrabutylphosphonium bromide was charged.
• the acid value was reduced to 10.0 in about 45 minutes.
• the 2850 g of polymer was cut to 50% nonvolatiles with styrene inhibited with 200 ppm of t-butyl cathecol.
• the mixture was heated slowly to 225° C., removing H 2 O and after holding for 15 to 16 hours, 1.2 g of Fascat 4100 catalyst (M&T Chemicals, Rahway, N.J.) was charged. Analysis showed the acid value was 43.1 and hydroxyl value was about 13.6, so about 12 g of NPG and 8 g DEG was charged. The cook stalled at an acid value of 34.6. Analysis showed the hydroxyl number to be about zero. This time the nitrogen flow was shut off and 21 g NPG and 11 g DEG was charged. In about 8 hours, the acid value dropped to 25.4 The temperature was reduced to about 160° C.
• Fascat 4100 catalyst M&T Chemicals, Rahway, N.J.
• Low profile additive #7 was prepared from recycled PET digested with a 60 mole percent diethylene glycol and 40 mole percent neopentyl glycol mixture replacing 2-methyl 1,3-propanediol.
• the charge to the 4-liter resin kettle was:
• the glycols and 960 grams of the PET were charged first. After the polymer had begun to melt into the glycol, remaining PET was charged. The pot temperature was set for 235° C., but began to boil vigorously at 225° C. About 2 ppm of Antifoam A eliminated the foaming.
• the PET was digested for about 4 hours and the adipic acid was added to repolymerize the PET. Water was removed as the kettle temperature was increased from 165° C. to 225° C. over an eight hour period. After six hours at 226° C., the [AV] was 37.8 and 1.25 grams of Fascat 4100 was charged. After nine hours at 226° C., the [AV] was 31.4 and the [OH] was 17.7.
• the [AV] and [OH] difference was adjusted with 24 grams adipic acid.
• the kettle was cooled to about 175° C. and 108 grams of Epon 828 and 2.9 grams of 70% tetrabutylphosphonium acetate catalyst were charged. In about 75 minutes, the [AV] was reduced to 13.1 and about 2550 grams of polymer were cooled and cut to 50% nonvolatiles in inhibited styrene.
• the mixture was heated slowly to 225° C., removing H 2 O and held for about 20 hours to an acid value of about 12.9 and hydroxyl value of about 14.
• About 800 g of the polymer was dissolved in 800 g of styrene using 0.28 g t-butyl catechol as an inhibitor.
• the mixture was warmed, under a nitrogen blanket, to ⁇ 70° C.
• About 1.6 g of dibutyl tin dilaurate was added as a catalyst and the mixture was held at temperature for ⁇ 3 hours.
• About 3.7 g of 2-ethylhexanol was charged to insure all of the isocyanate had been consumed.
• Formulation B shows good surface quality while Formulation A shows superior quality when the LPA is epoxy extended.
• Formulation B is better than Formulation E made from a blend of solely symmetrical glycols.
• Thermoplastic additives were prepared according to U.S. Pat. No. 4,056,561.
• PET oligomers and glycol monomers were prepared by reacting a mixture of recycle PET, ethylene glycol and diethylene glycol for about 3-4 hours at 230° C. Additional glycol were added to the oligomers to prepare a mixture which had a composition in the preferred ranges shown in the table between lines 45 and 55 column 2 of U.S. Pat. No. 4,054,561. Analysis of the mixture showed the hydroxyl number was about 550.
• the Empol 1018 dimer/trimer acid having an acid value of about 197 was used.
• thermoplastic with acid value of about 30 and hydroxyl of about 5-10 require about 525 g oligomer and 1660 g dimer acid (weight ratio 3.16) which is within the range of 1.3-3.5 acid/glycols 4,054,561.
• the final product had an [AV] of about 26 and was soluble in styrene at 50% N.V. It was not soluble, however, in a standard formulation of PET modified base resin Ashland ENVIREZ 8030 resin containing 57.5, 32.0 of the additive at 50% NV and 10.5 g styrene per 100 g of formulated resin. This solution rapidly separated into a thin upper layer ( ⁇ 40%) and thicker lower layer ⁇ 60° in 1-11/2 hours).
• a second thermoplastic additive was prepared according to U.S. Pat. No. 4,051,561 with a significantly lower ratio of dimer/trimer acid to glycol mixture. To accomplish this and maintain similar number average molecular weight and acid value for the product, it was necessary to adjust the glycol mixture to increase the oligomer content and reduce the hydroxyl number.
• the new glycol mixture was made by reacting a mixture of 613 g of oligomer from Example A ([OH] ⁇ 550) with 387 g of recycle PET resin at 235° C. for 3 1/2-4 hours. This yielded an oligomeric mixture having a hydroxyl value of about 325. Subsequently 436 g of oligomer were reacted with 842 g Empol 0108 dimer acid.
• thermoplastic A the standard formulation shown in Table 3 was mixed to prepare sheet molding compound in ASHLAND ENVIREZ 8030 base resin. Again, the thermoplastic additive was not soluble in the resin formulation, and the liquid resin separated into two approximately equal layers in 2-21/2 hours. Filled paste using Thermoplastic B was about double in viscosity compared to a sample using low profile additive #4 (52,000 centipoise vs.
• Sheet prepared with Thermoplastic B was allowed to thicken until the paste viscosity had reached 55 million centipoise. It was then molded into 12 ⁇ 12 laques at 1000 psi and 300° F. for 90 to 120 seconds.
• the plaques were superior to those from Thermoplastic A. No warpage was observed. Shrinkage control was adequate. The plaques had a very dull surface and visible glass print. With difficulty a LORIA surface quality measurement was made for that portion of the plaque where a surface reflection could be obtained. (Table 3). This measurement (151) is significantly poorer than that using low profile additive #4 (111). It was very difficult to obtain and should be considered a best case value for Thermoplastic B.
• Table 3 reports a comparison of terephthalic acid-containing low profile additives #4 and #5 from Table 2 in a base resin containing terephthalic acid from recycled polyethylene terephthalate polymer.
• Table 3 also reports the comparative tests with U.S. Pat. No. 4,054,561 Examples A and B.
• Table 3 shows the data obtained with the U.S. Pat. No. 4,054,561 dimer acid-trimer acid. Ashland Surface Quality Index was 151 compared with the surface quality of 100 or 111 from the diethylene glycol/recycle PET low profile additive and asymmetric glycol/recycle PET low profile additive of this invention. This change in surface quality from 151 to 100 or 111 is a substantial improvement in the low profile property of the saturated polyester additive of this invention over the low profile additive of the reference.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polyesters Or Polycarbonates (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 1996
  • 1996-02-02 US US08/590,033 patent/US5552478A/en not_active Expired - Lifetime
• 1997
  • 1997-01-29 WO PCT/US1997/001574 patent/WO1997028204A1/fr active IP Right Grant
  • 1997-01-29 AU AU22521/97A patent/AU2252197A/en not_active Abandoned
  • 1997-01-29 DE DE69737055T patent/DE69737055T2/de not_active Expired - Lifetime
  • 1997-01-29 ES ES97905691T patent/ES2276420T3/es not_active Expired - Lifetime
  • 1997-01-29 EP EP97905691A patent/EP0877771B1/fr not_active Expired - Lifetime
  • 1997-01-29 AT AT97905691T patent/ATE347574T1/de not_active IP Right Cessation

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